Enhanced DNA binding and activation of transcription factors NF-kappa B and AP-1 by acetaldehyde in HEPG2 cells.
J Biol Chem
; 275(19): 14684-90, 2000 May 12.
Article
en En
| MEDLINE
| ID: mdl-10799556
Because transcription factors NF-kappaB and activator protein-1 (AP-1) are known to regulate gene expression, we have analyzed the role of acetaldehyde in the activation of NF-kappaB and AP-1 in HepG2 cells. Binding activity and transactivation of NF-kappaB and AP-1 were determined by gel retardation assays and transfection of a luciferase reporter construct controlled by kappaB and AP-1 binding sites, respectively. Acetaldehyde enhanced the DNA binding of NF-kappaB and AP-1 by 1 and 4 h, respectively, increasing the kappaB- and AP-1-dependent luciferase expression. Supershift assays revealed the presence of NF-kappaB heterodimers p65/p50 and p50/p52, whereas nuclear c-Jun levels correlated with the DNA binding of AP-1. The enhanced binding of NF-kappaB to DNA by acetaldehyde in intact cells was accompanied by the proteolytic degradation of IkappaB-alpha. However, the addition of acetaldehyde to cytostolic extracts from untreated Hep G2 cells did not affect the DNA binding of AP-1 but activated the NF-kappaB heterodimer p65/p50 in the absence of IkappaB-alpha degradation. Preincubation of HepG2 cells with protein kinase C inhibitors abolished the enhanced DNA binding of NF-kappaB and AP-1 caused by acetaldehyde. Hence, these findings uncover a previously unrecognized role for acetaldehyde in the activation of NF-kappaB and AP-1, which may be of relevance in the alcohol-induced liver disease.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ADN
/
FN-kappa B
/
Factor de Transcripción AP-1
/
Acetaldehído
Límite:
Humans
Idioma:
En
Revista:
J Biol Chem
Año:
2000
Tipo del documento:
Article
País de afiliación:
España
Pais de publicación:
Estados Unidos